1. Field of the Invention
The present invention relates to an electroluminescent display and, more particularly, to an electroluminescent display in which an electromagnetic shield is adapted to shield a first power supply voltage line to prevent the occurrence of noise or the like on the power supply voltage due to internal or external electromagnetic waves.
2. Description of the Related Art
In recent years, various flat panel displays have been developed which are capable of reducing weight and volume which are disadvantages of a Cathode Ray Tube (CRT). Such flat panel displays include liquid crystal displays, field emission displays, plasma display panels, electroluminescent displays, and the like.
Among these displays, the electroluminescent display uses carriers, such as electrons and holes, to excite a fluorescent material to display images or video so that it may be driven by a low direct voltage and has a faster response speed. For these reasons, the electroluminescent display has been in the spotlight as the next generation display and research on new electroluminescent display products have accelerated in recent years.
An electroluminescent display can be classified into a passive matrix type and an active matrix type. The active matrix electroluminescent display has an active switching device arranged in each pixel. A voltage or current is supplied to drive each emitting device in response to the image data of the pixel.
An electroluminescent display includes a first upper power supply voltage line, a first lower power supply voltage line, a second power supply voltage line, a scan driver, a data driver, a first active power supply voltage line, and a pixel region.
The electroluminescent display includes the scan driver supplying a selection signal, the data driver supplying a data signal, the pixel region emitting light in response to the selection signal and the data signal respectively supplied from the scan driver and the data driver, the first upper and lower power supply voltage lines delivering first power supply voltages, the second power supply line delivering a second power supply voltage, and the first active power supply voltage line supplying the power supply voltages from the first power supply voltage lines and the second power supply voltage from the second power supply voltage line to the pixel region.
When the selection signal and the data signal are respectively supplied from the scan driver and the data driver to the pixel region, switching transistors drive transistors of the pixel region, and the first and second power supply voltages are supplied to the pixel region via the first power supply voltage lines and the second power supply voltage line so that each pixel of the pixel region emits light. Each of the first power supply voltages is opposite to that of the second power supply voltage.
However, the electroluminescent display described above has a problem that the waveform of the power supply voltage is distorted due to internally or externally supplied electromagnetic waves. That is, the power supply voltages delivered via the first upper and lower power supply voltage lines have noise which results from externally or internally supplied electromagnetic waves, thereby resulting in non-uniform brightness.